This invention relates to machines for producing concrete products such as concrete pipe, manholes, catch basins, and the like. The machines used to produce pipe employ the three basic steps of filling the forms, pressureheading concrete in the forms, and then stripping the forms from the pipe and allowing the pipe to cure. During the manufacturing process, a bell forming ring, commonly called a pallet, is placed at the bottom of the core and jacket to form one end of the pipe and support it during curing. After the form is filled with concrete, and during the pressureheading step, a spigot forming ring, called a header, is pressed into the wet concrete at the end of the pipe opposite the pallet ring to form the other end of the pipe. This header ring also is left in place during the curing of the concrete. Examples of concrete pipe-making machines are illustrated in Schmidgall U.S. Pat. No. 4,708,621 and Schmidgall U.S. Pat. No. 5,234,331.
After the concrete pipes have cured, the pallet and header rings must be removed. Also, since these rings are large metal rings and relatively expensive, they are reused, and the surfaces must be cleaned to remove all concrete residue and the rings oiled before reuse. Since several of the inside surfaces of these rings form the ends of the pipe that form the pipe joints when the pipes are installed, proper cleaning of the surfaces of the rings is important to production of high quality pipe. Moreover, if the outside surfaces are also not properly cleaned, a build up of dried concrete can prevent proper positioning and alignment of the rings when they are reused and set in place with the jacket and core to produce another pipe. In some instances, if the concrete is not removed, the build up can be so severe that the rings will jam and cause considerable problems during the stripping of the forms.
At the present time, it is common practice to remove, clean and oil the pallet and header rings manually, and if the worker is not careful, damage can be done to the pipe and the rings. More importantly, performing these tasks manually is a difficult, unpleasant and sometimes dangerous job. The ring is manually removed by hammering on the ring, and cleaning is commonly done by a worker using a power operated brush to remove the concrete build up. All of these tasks involve the use of heavy hand and power tools and repetitive movements, such as bending, lifting, etc. that can lead to work related physical and mental conditions. Anticipated governmental regulations may require new methods and systems that provide cumulative trauma disorder protection of all workers by imposing ergonomic standards on pipe manufacturers. One prior art system attempts to overcome the problems associated with and resulting from these manual tasks by automating the ring removal and cleaning operations in which the cured pipe is oriented vertically and one ring at a time is pulled from each end of the pipe. The rings are then placed on two turn tables, and a ring is cleaned by brushing on one turn table, and when the ring has been cleaned, the second turn table is automatically pivoted to place the second ring in position for cleaning while the now-brushed ring is automatically removed and a second ring is placed on that turn table. The process then repeats itself, and use of the two turn tables allows a cleaned ring to be removed and a dirty ring to be placed on one turn table while one ring is being cleaned on the other turn table. This prior art system is relatively slow and is complex and expensive. Moreover, the system uses only brushes, and not infrequently, the brushes are incapable of removing some of the concrete build up. When this occurs, that build up must be manually removed. Moreover, the prior art systems are limited to handling rings of a single diameter at a time. To accommodate rings of a different diameter or of a different type (i.e. headers or pallets) the set up must be changed during which time the cleaning operation is shut down. This is a distinct disadvantage, especially since concrete pipe manufacturers frequently produce pipes of different sizes during a single operation. Equipment for accomplishing this is illustrated in Schmidgall U.S. Pat. No. 4,708,621. Therefore, in a plant operation which is producing different pipe sizes during a single cycle of operation, the rings must be sorted and grouped by size and cleaned by size in order to minimize the cleaning set up time.
It is highly desirable in pipe-making operations to be able to quickly and efficiently perform all the cleaning functions. In fact, overall plant production can in many cases depend upon the ability to quickly remove and clean the rings from the pipe for reuse.
There is therefore a need for an improved method and system for removing the rings from the cured pipe in a safe, rapid and efficient manner while minimizing any damage to the pipe.
There is a further need for an improved method and system for cleaning the pallet and header rings for reuse, including a system that will also remove the concrete build up that brushes of the prior art systems cannot presently remove.
The methods and systems of the invention will fulfill these and other needs by providing a fully automated system for removing the rings and cleaning and oiling them without the intervention of an operator. By eliminating the manual labor presently required, worker physical and mental health and safety will be improved. The invention also will provide an automated system that will meet the anticipated standards relating to cumulative trauma disorder prevention. Moreover, the methods and systems of the invention will be environmentally sound, since escape of dust and oil fumes into the environment will be controlled.
The advantages and features of the methods and systems of the invention will become more evident from the detailed description of the preferred embodiments set forth hereinafter.